1. Field of the Invention
The present invention relates to a wiring member, a resin-coated-metal part and a resin-sealed semiconductor device, and a manufacturing method for the resin-coated metal part and the resin-sealed semiconductor device, and in particular to technology for improving adhesion between a metallic material and a resin material.
2. Related Art
Resin materials are widely used in semiconductor devices and wiring members.
In general, a semiconductor device such as an integrated circuit (IC) or large scale integrated circuit (LSI) are manufactured by a process in which a predetermined semiconductor element is connected to wiring leads by wire bonding etc., a portion of the wiring leads are exposed to the exterior, and packaging by resin sealing is performed by adhering resin to the wiring leads in this condition.
FIGS. 21A to 21D are schematic cross-sectional diagrams showing manufacturing steps for a resin-sealed QFP (Quad Flat Package) semiconductor device.
First, a semiconductor chip 94 is mounted on a die pad 93b of a wiring lead 93 (including die pads 93a and 93b), and the semiconductor chip 94 and the die pads 93a and 93b are connected by a wire 95.
Thereafter, the wiring lead 93 is disposed on a fixed die 92 (FIG. 21A).
Next, a movable die 91 is pressed on the fixed die 92 such that the dies 91 and 92 are closed together to form an inner space (cavity 97) therebetween. A thermoset resin is injected into the cavity 97 via a gate 96 provided in the movable die 91, thereby resin-sealing the semiconductor chip 94 etc. (FIG. 21B).
After hardening the thermoset resin, the dies 91 and 92 are opened, and an ejector pin (not depicted) is used to press out a resin cast 9z. Then outer leads 931a of the resin cast are bent, thereby obtaining a completed semiconductor device 9 (FIG. 21D).
The above were exemplary manufacturing steps for a QFP semiconductor device. There are other types of semiconductor devices, such as a light emitting diode (LED) device. An LED device is manufactured by, for example, forming a substrate in the interior of a mortar-shaped reflector such that a portion of a wiring lead is exposed, and mounting an LED element on the wiring lead in the reflector to connect the LED element and the wiring lead, and thereafter filling the interior of the reflector with a transparent sealing resin. In place of epoxy resin, silicone resin with a higher light transmittance is currently becoming more widely used.
Furthermore, film carrier tape, examples of which are TAB (Tape Automated Bonding) tape, T-BGA (Tape Ball Grid Array) tape, and ASIC (Application Specific Integrated Circuit) tape, and which is used in the implementation of electrical parts of the IC, LSI, etc., has a structure in which an insulating film composed of a polyimide etc., a wiring pattern layer composed of Cu, and a solder resist layer are laminated in the stated order. Here, resin materials are used as the insulating film and the solder resist layer.
Patent document 1: Japanese Laid-Open Patent No. 2731123
Patent document 2: Japanese Patent Application Publication No. H10-329461
Patent document 3: Japanese Patent Application Publication No. 2002-33345
Patent document 4: Japanese Patent No. 3076342
However, resin casts in semiconductor devices and LED devices, as well as film carrier tape have the following issues.
The first issue is a problem in which during the injection of the sealing resin, the resin not only fills the intended resin cast area, but also adheres to wiring lead areas that are not part of the intended resin cast area. As shown in the enlarged portion P of FIG. 21B in the manufacturing steps for the semiconductor device, there is the possibility that due to the injection of the resin material at a constant pressure, resin thin films (so called resin burrs) are formed on surfaces of the outer leads 931a of the wiring lead 93 when the resin material flows into gaps 900 between the dies (FIG. 21C). These gaps 900 occur due to imprecision between the dies 91 and 92, and the resin burrs 98a are formed due to the outflow of the resin material that occurs when the pressure during injection becomes directed into the gaps 900. The existence of the resin burrs 98a makes it possible for there to be problems with the connection strength and electric contact between the outer leads 931a and a substrate 99 in the next step. Although the dies 91 and 92 may be shaped with higher precision in order to prevent this problem, not only do costs rises significantly due to die designing, but also it is very difficult to completely prevent the occurrence of gaps due to problems with machine precision. Patent documents 1 to 3 for example propose measures for preventing gaps between the metal dies. However, the technology disclosed in patent documents 1 and 2 increases the pressure applied to the wiring lead of the dies, and therefore there is the danger of applying an excessive deforming stress to the wiring lead, and there is the fear of damaging the dies or the wiring lead. Patent document 3 discloses technology for improving closure of the dies by pre-adhering tape to portions of the dies where the gaps occur. However, even if such tape is used, there is the possibility of problems such as detachment of and damage to the tape in the injection step which involves mechanical frictional force under relatively high temperatures. Moreover, providing the tape still has problems with respect to a decrease in manufacturing efficiency and a rise in manufacturing costs.
Accordingly, assuming that the occurrence of resin burrs cannot be prevented, it becomes necessary to provide a step for eliminating the resin burrs 98a before the step for connection with the substrate. This also has problems with respect to a decrease in manufacturing efficiency and a rise in manufacturing costs.
The second issue is a problem when using silicone resin as the sealing resin in an LED device. Although able to maintain a high transparency, silicone resin has a higher linear expansion coefficient than epoxy resin etc. There is therefore the possibility that the silicone resin will heat-shrink due to thermal change (so-called thermal history) in the resin material in the step for injecting the silicone resin on the substrate. Accordingly, there is detachment between the silicone resin and the wiring lead, and there is the possibility of problems such as performance degredation due to poor contact, or insufficient contact strength.
Although there is also a technique of providing an Ag plating on surfaces of the wiring lead in order to improve luminous efficiency in an LED device, there is an issue regarding the Ag plating coat, which is mentioned here as the third issue. Although known to have a high reflection coefficient with respect to long wavelength visible light, Ag materials have a comparatively low reflection coefficient with respect to short wavelength light (approximately 500 nm or below). Accordingly, a sufficient reflection coefficient cannot be obtained when a blue, violet, ultraviolet, LED etc. is implemented in an LED device, in which case there is the possibility of not, obtaining an intended luminous efficiency.
The fourth issue is a problem in a case of, as shown in patent document 4, providing an Sn plating on the wiring pattern layer in the film carrier tape. An Sn coating layer is provided on the surface of the wiring pattern layer in order for connection with implementation parts by soldering. The ends of the solder resist layer peel due to the heated atmosphere in the plating step, and localized batteries are formed between an area under the peeled solder resist layer and another area on the surface of the wiring pattern layer due to the difference in ionization tendency of Sn ions and Cu ions (FIG. 22A). As a result of the formation of the localized batteries, erosion areas are formed due to Cu ions that have eluted into the surface of the wiring pattern layer. There is therefore the possibility of problems with respect to a reduction in the mechanical strength of the film carrier tape after the Sn plating has been performed, and with respect to the plating not being formed evenly.
As mentioned above, it can be said that there are still matters to be resolved when using resin materials in the fields of semiconductor devices and film carrier tape.